Ab initiostudies of electronic structure of defects on the Te sites in PbTe

Abstract

ABSTRACTAb initioelectronic structure calculations have been carried out to understand the nature of anionic defect states in PbTe. We find that Te vacancies strongly perturb the electronic density of states (DOS) near the band gap region. New states of predominantly Pb p character appear in the band gap. Iodine is an ideal substitutional defect and a donor. Sulpher and Selenium do not affect the states near the conduction band minimum but suppress the DOS near the valence band maximum. These results have important implications on the thermoelectric properties of PbTe and PbTexM1−x(M=S, Se) ternary systems.